A130288 - OEIS

A130288

Record indices of A130280: integers n>0 for which min{ m>1 | (2n+1)^2(m^2-1)+1 is a square} < oo but bigger than for all preceding n.

%I #5 Jun 14 2017 00:31:09

%S 1,2,11,14,18,23,27,34,38,44,54,59,74,158,179,284,524

%N Record indices of A130280: integers n>0 for which min{ m>1 | (2n+1)^2(m^2-1)+1 is a square} < oo but bigger than for all preceding n.

%C Most elements of this sequence seem to be 1,2 or 4 times a prime.

%C Corresponding values of A130280 are given in A130289. - _M. F. Hasler_, May 24 2007

%o (PARI) A130288(L=999,S=1)={local(R,T);for(n=S,L, if(issquare(n) || R>=T=A130280(n),next); print1(n", ");R=T)}

%Y Cf. A084702, A130280, A130283, A130284, A130289.

%K nonn

%O 1,2

%A _M. F. Hasler_, May 24 2007